The present invention relates to a liquid supply method and a liquid supply system using a negative pressure to supply liquid to an outside, and more particularly to a liquid supply method usable with a liquid ejection recording apparatus which effects printing on recording material using a recording head to which liquid is supplied, a liquid supply system, an exchange liquid accommodating container and head cartridge usable with such a system.
Conventionally, a liquid supply method using a negative pressure for supplying liquid to the outside is known in an ink jet recording apparatus field, wherein for example an ink container for permitting supply of liquid to an ink ejection head with a negative pressure, and wherein the ink container is made integral with the recording head ((head cartridge). The head cartridge is classified into a type wherein the recording head and the ink container (ink accommodating portion) are normally integral, and a type wherein the recording means and the ink accommodating portion are separate, which are both separable relative to the recording device, and are made integral when they are used.
In such a liquid supply system, the easiest way of producing the negative pressure is to use capillary force of a porous material. The ink container of this type is provided with a porous material such as sponge which is accommodated preferably under compression and which occupies the entirety of the inside of the container, and with an air vent for permitting smooth ink supply by introduction of the air during the printing. However, this type involves a problem that ink accommodation efficiency per unit voltage is low since the porous member is used to retain the ink. EP0580433 which has been assigned to the assignee of this application has proposed an Ink container including a negative pressure producing material chamber, an ink accommodating chamber (reservoir) and a fluid communication part therebetween, wherein the ink accommodating chamber is substantially hermetically sealed, and the negative pressure producing material chamber is open to the ambience. EP0581531 also proposes a structure wherein the above-described o is exchangeable.
Such an ink container is advantageous in that air is permitted go into the ink accommodating chamber with discharge of the ink from the ink accommodating chamber into the negative pressure producing material chamber (air-liquid exchanging operation), so that ink can be supplied to the outside with a substantially constant negative pressure during the air-liquid exchanging operation.
EP0738605 which has been assigned to the assignee of this application proposes a liquid accommodating container including a casing having a substantially prism configuration, and a liquid accommodating portion which is deformable with discharge of the liquid therefrom said accommodating portion having an outer shape similar or equivalent to an inner shape of the casing, wherein in each side of the prism-like shape, the thickness at the corner portions of the side is smaller than the central portion thereof. In the liquid accommodating container, the accommodating portion deforms or contracts with the discharge of the liquid (without air-liquid exchange) so that liquid is supplied with the negative pressure. This container is advantageous in that position of the ink container is not limited as compared with an ink containing bladder which is conventional. Additionally, since the ink is directly retained (substantially without use of porous material), the ink accommodation efficiency is high.
The ink container of the type having the negative pressure producing material chamber and the ink accommodating chamber has a fixed accommodation space. In order to discharge the ink therefrom into the negative pressure producing material chamber, air-liquid exchange is used, by which the air is introduced into the ink accommodating chamber. Therefore, when the ink is supplied out into the negative pressure producing material chamber, the corresponding amount of the air is introduced, so that ink accommodating chamber contains both of the air and the ink. The air may expands due to the ambient condition change (temperature variation during 24 hours) with the result that ink is discharged into the negative pressure producing material chamber from the ink accommodating chamber. Therefore, a buffer space has to be provided in the negative pressure producing member or material in consideration of a practically maximum volume determined by the expansion and the resulting amount of ink motion in various conditions. In the conventional air-liquid exchanging operation, the ink discharge from the ink accommodating chamber into the negative pressure producing material chamber is directly interrelated with the introduction of the air through the communicating portion, and therefore, when a large amount of the ink is discharged from the negative pressure producing material chamber to the outside (liquid ejecting head) in a short period of time, the ink supply from the ink accommodating chamber into the negative pressure producing material chamber with the air-liquid exchanging operation is unlikely to follow the abrupt ink consumption.
Accordingly, it is a principal object of the present invention to provide a liquid supply method, a liquid supply system, an ink container and an ink jet cartridge wherein the ink is contained in the negative pressure producing material chamber and the ink accommodating chamber (reservoir) and wherein the volume of the buffer space required by the negative pressure producing material chamber can be reduced even in view of various conditions, can be reduced, and the ink supply is carried out with a stable negative pressure during use of the ink in the ink accommodating chamber while permitting large expansion of the air introduced by the air-liquid exchange.
It is another object of the present invention to provide a liquid supply system and a liquid container usable with the system wherein the ink accommodating chamber (liquid accommodating container) is exchangeable in addition to or independently of the first object.
It is a further object of the present invention to provide a related devices such as a head cartridge related with the liquid supply method and the liquid supply system. The inventors have analyzed in detail the ink accommodating chamber containing the air in an ink container having the negative pressure producing material chamber, the ink accommodating chamber and the communication port therebetween. The supply of the ink from the ink accommodating chamber into the negative pressure producing material chamber occurs in interrelation with the introduction of the air.
The expansion of the air in the ink accommodating chamber is unavoidable, but the inventors have considered allowing the expansion of the air in the ink accommodating chamber.
It is a further object of the present invention to provide a According to an aspect of the present invention, there is provided a liquid supply method comprising a step of preparing a negative pressure producing material chamber, including a liquid supply portion for permitting supply of the liquid to an outside and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid; a step of preparing a liquid containing chamber having a liquid containing portion for accommodating the liquid, said liquid containing portion forming a substantially sealed space except for fluid communication with the negative pressure producing material chamber; a first liquid supply step of permitting supply of the liquid to the outside by permitting movement of the liquid into said negative pressure producing material chamber from said liquid containing portion without introduction of the air into the liquid containing chamber with a negative pressure while permitting decrease of a volume of said liquid containing portion; a second liquid supply step, after said first liquid supply step, of permitting supply of the liquid to the outside by permitting movement of the liquid into said negative pressure producing material chamber from said liquid containing portion with introduction of the air into the liquid containing portion.
According to this method, the liquid containing portion deforms while maintaining a balance in the negative pressure with the negative pressure producing member. Therefore, even if the air expands in the liquid containing portion due to the ambient condition change, the liquid containing portion restores its shape upon an abrupt change so that influence of the change can be decreased. If the change is not abrupt, the influence of the expansion can be decreased by both of the negative pressure producing member and the liquid containing portion while the balance is eventually maintained with the negative pressure producing member. Therefore, the voltage of the buffer space in the negative pressure producing material chamber can be reduced even in view of various use condition.
In the second liquid supply process, the air is introduced into the liquid containing portion, so that liquid in the liquid containing portion is used up substantially without an unusable remaining amount ink, and the negative pressure difference between at the time of the start of the liquid discharge from the liquid containing portion and at the time of the end thereof, can be smaller than that when the liquid containing portion alone is used as a negative pressure producing container. As compared with the conventional type ink container having the negative pressure producing material chamber, the ink accommodating chamber and the communication port therebetween, the allowance to the air expansion is larger. Even if a large amount of the ink is consumed in a short period of time, the liquid supply from the liquid containing portion into the negative pressure producing material chamber is smooth since the liquid containing portion is deformable. Therefore, the ink supply is stabilized when the ink in the liquid containing portion is consumed. According to another aspect of the present invention, there is provided a liquid supply system, using a liquid supply container including a liquid containing portion for accommodating liquid in a sealed space; a negative pressure producing material container, which accommodating container is detachably mountable relative to the liquid supply container and which is capable of effecting air-liquid exchange wherein air is introduced into said liquid containing portion, and the liquid is discharged through a communicating portion communicating with said liquid accommodating portion; the improvement comprising: said liquid containing portion of said liquid supply container is capable of producing a negative pressure while deforming; and wherein when the liquid supply container is mounted to said negative pressure producing material chamber, the liquid is permitted to move from said liquid containing portion into said negative pressure producing material chamber.
According to this system, even if the accommodating container for the negative pressure producing material does not contain the liquid in the neighborhood of the communicating portion to the liquid accommodating container, the liquid can be moved from the liquid accommodating container into the negative pressure producing member using the capillary force in the negative pressure producing material chamber upon the mounting of the liquid accommodating container to the negative pressure producing material chamber, so that liquid in the exchanged liquid accommodating container can be assuredly used by the simple mounting, irrespective of the liquid retaining state of the negative pressure producing member adjacent the connecting portion. Thus, a practical liquid supply system with stabilized liquid supply can be provided.
By movement in a part of the liquid in the liquid containing portion into the negative pressure producing material container upon the connection, the liquid containing portion is deformed, and therefore, influence of the expansion of the air in the liquid containing portion due to the ambient condition change can be eased. The present invention provides an ink container and an ink jet cartridge usable with the liquid supply method and the liquid supply system.
More particularly, according to a further aspect of the present invention, there is provided a liquid container, comprising a negative pressure producing material chamber, including a liquid supply portion for permitting supply of the liquid to an outside and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid; a liquid containing chamber having a liquid containing portion for accommodating the liquid, said liquid containing portion forming a substantially sealed space except for fluid communication with the negative pressure producing material chamber; wherein said liquid containing portion deforms with discharge of the liquid therefrom while producing a negative pressure.
The ink jet cartridge provided by the present invention comprises the above-described ink container and a recording head for effecting recording by ejecting the liquid to the outside. Further, the present invention provides an exchange liquid accommodating container usable with the liquid supply system.
More particularly, there is provided a liquid accommodating container detachably mountable relative to a negative pressure producing material container, having a liquid supply portion for supplying liquid to an outside and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid, comprising a liquid containing portion for accommodating the liquid, which forms a substantially sealed space except for fluid communication with the negative pressure producing material chamber; and sealing means for sealing said communicating portion relative to said negative pressure producing material chamber.
Furthermore, there is provided a liquid accommodating container detachably mountable relative to a negative pressure producing material container, having a liquid supply portion for supplying liquid to an outside and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid, comprising a liquid containing portion for accommodating the liquid, which forms a substantially sealed space except for fluid communication with the negative pressure producing material chamber; and a casing having an inner shape equivalent or similar to an outer shape of said liquid containing portion and having an air vent for introducing the ambience; sealing means for sealing said communicating portion relative to said negative pressure producing material chamber.
The present invention is suitably applicable to a head cartridge used in an ink jet recording field.
More particularly, there is provided a head cartridge comprising a recording head for ejecting the liquid; a negative pressure producing material chamber, including a liquid supply portion for permitting supply of the liquid to said recording head and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid; a liquid containing chamber having a liquid containing portion for accommodating the liquid, said liquid containing portion forming a substantially sealed space except for fluid communication with the negative pressure producing material chamber; and wherein said liquid containing portion deforms with discharge of the liquid therefrom while producing a negative pressure; wherein said recording head and said negative pressure producing material chamber are integral with each other.
A further aspect of the present invention provides a further method. More particularly, it provides a liquid supply method comprising a step of preparing a negative pressure producing material chamber, including a liquid supply portion for permitting supply of the liquid to an outside and an air vent for fluid communication with ambience, for accommodating a negative pressure producing member for retaining the liquid; a step of preparing a liquid containing chamber having a liquid containing portion for accommodating the liquid, said liquid containing portion forming a substantially sealed space except for fluid communication with the negative pressure producing material chamber; a step of moving the liquid from said liquid containing portion into said negative pressure producing material chamber without introduction of air into said liquid containing chamber with a negative pressure while permitting decrease of a volume of said liquid containing portion.
According to this method, the liquid in the liquid containing portion is usable without introduction of the air into the liquid containing portion, and therefore, even if the limitation to the inside volume of the liquid containing chamber is eased, change of the ambience is accommodatable.
In this specification, the negative pressure producing material container and the liquid accommodating container are generally used where they are separable from each other, and the negative pressure producing material chamber and the liquid containing chamber are used when they are separable or not separable.
The region not filled with the liquid adjacent the air vent of the first chamber means a part the negative pressure producing member not filled with the ink as well as the space not having the negative pressure producing member (buffer portion).
These and other objects, features and advantages of the present invention will become more apparent upon a consideration of the following description of the preferred embodiments of the present invention taken in conjunction with the accompanying drawings.